Development of the treatment system for water polluted with organic chlorine compounds by using photocatalysis in the gas-phase

用有机氯化物化合物对地表水和土壤的污染，例如三氯化物和四氯化物有严重的问题，一个用于处理这类化合物的系统，将空气和气体相光电分析组合在目前的研究中开发出来。对原则性反应机制的基本研究等的实验，以及对实际系统的发展的实际研究，已经被运送到了.1。使用批处理反应器作为后续反应器的基础研究的结果;1）三氯化乙烯（或四氯化乙烯）的光分解分解，当一个TiO-D22-D2光催化剂在反应前被预先照亮时。这被认为是为了从TiO-D22-D2-D2-D2-光催化剂表面上去除水分子和羟基组。2）第二次和第三次反应仍然被加速，当使用相同的光催化剂时，磷酸酶和二氯乙酰氯化物被检测到作为（中间）产品。在固定的重复反应中的加速被认为可以用这样的复合物启动链式反应。4）关于反应机制的基本研究是为了在一个试点植物连续反应器中提供有用的信息，以便尽量减少有害的按产品的数量。使用一个试点工厂系统的实际研究结果如下;1）一个试点工厂在实际地面水中处理有机氯化合物，成功地利用航空和光分析的组合构建。被四氯乙烯污染的地面水一直很纯净：2）在气体排放中检测到的标准没有有害的化合物。3）该植物连续五周运营。实际的数据被收集到显示了实际大型植物的构造的很大可能性。

Pollution of groundwater and soils with organic chlorine compounds, such as trichloroethylene and tetrachloroethylene has been serious problems, A system for the treatment of such compounds using a combination of aeration and gas-phase photocatalysis was developed in the present study. Experiments for the fundamental study to elucidate reaction mechanisms, etc. and the practical study for the development of the actual system were carried out.1. Results of the fundamental study by using a batch reactor are as follows ;1) The photocatalytic degradation of trichloroethylene (or tetrachloroethylene) was accelerated, when a TiOィイD22ィエD2 photocatalyst was pre-illuminated with UV light before the reaction. This was supposed to be due to desorption of water molecules and hydroxyl groups from the surface of the TiOィイD22ィエD2 photocatalysts.2) The second and third reactions were still accelerated, when the photocatalytic degradation reaction was repeated by using the same photocatalyst.3) Phosgene and dichloroacetylchloride were detected as the (intermediate) products. The acceleration of the repeated reactions stated above was supposed to be due to the chain reaction initiated with such compounds.4) The fundamental study on reaction mechanisms was thought to give useful information to minimize formation of harmful by-products in the continuous reactor of a pilot-plant scale.2. Results of the practical study using a system of a pilot-plant are as follows ;1) A pilot plant to treat organic chlorine compounds in the actual groundwater was constructed in success using the combination of aeration and photocatalysis. The groundwater polluted with tetrachloroethylene was well purified continuously.2) No harmful compounds over the standard were detected in the gaseous exhaust.3)The plant was operated continuously for five weeks. Practical data were obtained to show much possibility of the construction of actual larger plant.